It is increasingly recognized that patient reported outcomes (PROs) are important outcomes to measure effectiveness of proposed therapies. A PRO is a measurement of the patient's health and well being from their perspective that is reported directly from the patient. The measurement and evaluation of PROs contribute to patient-centered care which is a key ingredient in provision of health care quality as noted by the Institute of Medicine. Utilizing PROs as a secondary outcome in an interventional trial can aid in understanding the effectiveness of the intervention and provide insight into aspects of a patient's well being. This proposed project seeks to determine the health-related quality of life (HRQL) and short term functional outcomes of children presenting with an acute sickle cell pain episode who are randomized to receive treatment with magnesium (Mg) or placebo, the parent trial to this proposed project. This proposed project builds on our previous work in HRQL and short term functional outcomes and is uniquely able to utilize this parent clinical trial to evaluate the effectiveness of drug therapy on these PROs. The overall goal of this project is to determine the HRQL and short term outcomes of children treated with intravenous magnesium during an acute painful crisis. We hypothesize that children in the treatment arm will have better HRQL at completion of Mg therapy and better short term outcomes at follow-up than those receiving placebo. In addition, our laboratory has completed phase 3 in the instrument development of a disease specific HRQL measure for sickle cell disease. We propose as an exploratory aim to determine the responsiveness and minimally important difference (MID) of this measure to further define its psychometric properties in the setting of the parent clinical trial. We hypothesize that the PedsQL Sickle Cell Disease module will be responsive to change in health status of the child over time and that we will define the MID with an anchor and distribution- based method successfully utilizing the design of the parent clinical trial. This proposed project will assess HRQL at time of presentation to the emergency room with an acute sickle cell pain episode, around the time of the last dose of study medication/placebo, one week post-discharge from the hospital, and one month post-discharge from the hospital. In addition, the following short term outcomes will be assessed one week and one month post-discharge from the hospital: 1) Days of work/school missed by primary caretaker, 2) Days of school missed by child and 3) Pain score (0-10) on standard pain scale.